90.2(C) Installations Covered.This Code covers the installation and removal of electrical conductors, equipment, and raceways; signaling and communications conductors, equipment, and raceways; and optical fiber cables for the following:    (1) Public and private premises, including buildings, structures, mobile homes, recreational vehicles, and floating buildings    (2) Yards, lots, parking lots, carnivals, and industrial substations    (3) Installations of conductors and equipment that connect to the supply of electricity    (4) Installations used by the electric utility, such as office buildings, warehouses, garages, machine shops, and recreational buildings, that are not an integral part of a generating plant, substation, or control center    (5) Installations supplying shore power to ships and watercraft in marinas and boatyards, including monitoring of leakage current    (6) Installations used to export electric power from vehicles to premises wiring or for bidirectional current flow 90.2(D) Installations Not Covered.This Code does not cover the following:    (1) Installations in ships, watercraft other than floating buildings, railway rolling stock, aircraft, or automotive vehicles other than mobile homes and recreational vehicles    Informational Note: Although the scope of this Code indicates that the Code does not cover installations in ships, portions of this Code are incorporated by reference into Title 46, Code of Federal Regulations, Parts 110–113.    (2) Installations underground in mines and self-propelled mobile surface mining machinery and its attendant electrical trailing cable    (3) Installations of railways for generation, transformation, transmission, energy storage, or distribution of power used exclusively for operation of rolling stock or installations used exclusively for signaling and communications purposes    (4) Installations of communications equipment under the exclusive control of communications utilities located outdoors or in building spaces used exclusively for such installations    (5) Installations under the exclusive control of an electric utility where such installations        a. Consist of service drops or service laterals, and associated metering, or        b. Are on property owned or leased by the electric utility for the purpose of communications, metering, generation, control, transformation, transmission, energy storage, or distribution of electric energy, or        c. Are located in legally established easements or rights-of-way, or        d. Are located by other written agreements either designated by or recognized by public service commissions, utility commissions, or other regulatory agencies having jurisdiction for such installations. These written agreements shall be limited to installations for the purpose of communications, metering, generation, control, transformation, transmission, energy storage, or distribution of electric energy where legally established easements or rights-of-way cannot be obtained. These installations shall be limited to federal lands, Native American reservations through the U.S. Department of the Interior Bureau of Indian Affairs, military bases, lands controlled by port authorities and state agencies and departments, and lands owned by railroads.Informational Note to (4) and (5): Examples of utilities may include those entities that are typically designated or recognized by governmental law or regulation by public service/utility commissions and that install, operate, and maintain electric supply (such as generation, transmission, or distribution systems) or communications systems (such as telephone, CATV, Internet, satellite, or data services). Utilities may be subject to compliance with codes and standards covering their regulated activities as adopted under governmental law or regulation. Additional information can be found through consultation with the appropriate governmental bodies, such as state regulatory commissions, the Federal Energy Regulatory Commission, and the Federal Communications Commission.90.2(F) Special Permission.The authority having jurisdiction for enforcing this Code may grant exception for the installation of conductors and equipment that are not under the exclusive control of the electric utilities and are used to connect the electric utility supply system to the service conductors of the premises served, provided such installations are outside a building or structure, or terminate inside at a readily accessible location nearest the point of entrance of the service conductors.

Rapid shutdown requirements for PV systems have spurred innovations within the industry since the requirement first appeared in the 2014 National Electrical Code (NEC). The requirements imposed by rapid shutdown often seemed ahead of their time. So much so that the 2017 Code provided an allowance to waive a specific subsection for two years to allow the industry to catch up and create products to meet the Code. One of these delayed provisions in 2017 allowed systems “listed or field labeled as a rapid shutdown PV array” to provide the necessary limits of PV conductors within the array boundary. The Code-making panel (CMP) recognized such a listing would eventually exist and proactively provided the industry with a way to meet this requirement. Then in 2020, NEC used an informational note bringing attention to UL standard 3741, Photovoltaic Hazard Control, specifically to address a method to meet this requirement. It wasn’t until late 2021 that the industry started to see commercially available equipment with the UL3741 listing. In this blog Ryan gives an overview of new pathways to achieve rapid shutdown compliance via UL3741 listing.